The present invention relates to an aligning assembly for use in prosthodontics, occlusion diagnosis and/or occlusion therapy in general, and more particularly to such an assembly which includes rigid upper jaw and lower jaw components which are connected to one another, after being properly positioned with respect to one another, to form the assembly for further use in dental work.
Aligning assemblies of this type are already in use and usually they include an upper jaw plate and a lower jaw plate one of which is provided with a bore in which there is received an externally threaded pin which is introducable into the other jaw plate.
One conventional aligning assembly of this kind has, in common with other similar aligning assemblies, both of the plates made of a metallic material. In addition thereto, there is provided a gauging support of a synthetic plastic material which is adjustably connected with the lower jaw plate by means of a pin-and-slot connection, the gauging support having a recess into which the point of the pin affixed to the upper jaw plate is elastically introducible. The alignment provided in an assembly of this type by means of the pin has considerable advantages when compared to the manual taking of the bite, especially with respect to the exact adjustment of the two condyles in the corresponding hinges.
In this conventional assembly, the two biting plates are fittingly positioned on the upper jaw or on the lower jaw, respectively, whereafter the patient is asked to conduct anterior-posterior and lateral movements of his lower jaw relative to the upper jaw. During these movements, the point of the pin draws a centering mark on the corresponding surface of the lower jaw plate which has been previously provided with a coating, such as a color coating. Thereafter, the dentist so positions the synthetic plastic material gauging support on the lower jaw plate that the recess of the gauging support registers with the centering mark. Then, the gauging support is fixed in position with respect to the lower jaw plate by means of a screw which enters the slot of the gauging support. Thereafter, the biting plates are repositioned in the oral cavity of the patient. After this happens, the patient is advised to close his mouth with a slight pressure, thus introducing the tip of the pin in the recess of the gauging support. After this, the dentist introduces an impression mass between the two plates. When the impression mass has hardened, both of the biting plates can be jointly removed from the oral cavity of the patient.
While this conventional arrangement is suited for precision work, the fact remains that this type of an aligning assembly has not yet been so widely used as it would deserve, particularly in view of the fact that the use of the known aligning assembly is relatively complicated and not free from sources of errors. So, for instance, the adjustment of the gauging support and the fixation by the impression mass which, more often than not, includes plaster and similar substances, are cumbersome operations which can lead to a mistaken taking of the bite. During the fixation with the plaster, it often happens that the biting plates are shifted relative to one another while the patient, particularly a nervous patient, moves his or her cheeks or jaws, finding this operation uncomfortable. When the tip of the pin is to be introduced into the recess of the gauging support during the taking of the bite, there exists the danger that the gauging support may become displaced. Furthermore, it cannot be always exactly ascertained whether the patient has indeed hit the recess of the gauging support or whether the gauging support remained in its position during the closing of the patient's mouth. A further source of errors is to be seen in the fact that the exact adjustment of the gauging support with respect to the centering mark is often rendered very difficult by reflection in the synthetic plastic material. Moreover, the possibilities of application of the known aligning assembly are drastically limited by the fact that the conventional aligning assembly can be used only on jaws which do not have any teeth whatsoever.